How can I make my alcohol stove more effecient?

[The Will]

I'm very pleased with everything about my home made alcohol stove with one exception. The top of the flames are approximately 7 inches high (from flame tip to stove top). This results in the flames "licking" up the sides of my cup rather than being concentrated on the under side. My boil times are generally 6:30 minutes for 9-10oz of water--this seems slow compared to other posts/reviews I have read, and I'm certain this is due to all the heat loss from the top of the flames doing no "heating work" what-so-ever.

Any suggestions?


The stove is a standard pop can stove, made from Red Bull cans (small). Burner holes were made with a plastic headed push-pen and they are spaced 2mm apart all around the circumference of the top of the stove.



The Will
MEGA '97

[jlb2012]

I had similar problems with the beer can "pot" that I use and finally I tried something that seems to work OK - the aluminum bottom to a tea candle - very light and it holds just enough alcohol to boil 1.75 cups of water which is what I generally use for my meals. The only adjustments to be done are to take the candle out - nothing else needs to be done. Note the time to boil will still be longish (7-8 minutes) but the flames generally stay under the pot and I don't use as much alcohol as when I was using an Ion stove for the pot.

Another possibility is to change the pot to one with a wider base - spreads the flames out more for faster boiling.

[SGT Rock]

What is your pot to stove distance?

[The Will]

The pot to stove distance is within 4-5cm.

I considered using a taller pot support in an effort to remedy the problem, but isn't that 7 or so inch flame height a bit out of the ordinary? Don't alcohol stoves usually exhibit a short, simmer-like flame? (It's is the same problem whether I burn Heet or denatured alcohol).

Thanks.



The Will
MEGA '97

[SGT Rock]

Depending on the stove and how much fuel it allows to burn, the height of an exposed flame (one without a pot in the way) could be up to 12" and bright yellow in my experience. The interaction between the pot and the stove can choke the stove. I was going to suggest that you try reducing the pot height down to abou 1/2"-3/4" (about 1-1/2 to 2cm). See if that helps control the flame.

[Miss Janet]

Try making a closed design stove that you can sit your pot on and eliminate a pot stand. My Kiss stove... Keep it simple, stupid ... has been working very well and a lot of hikers are using it this year.

[art to linda]

Where can I find the plans for your stove? I'm looking at different types and the simpler the better, "KISS stove" sounds interesting.

[SGT Rock]

I've got a stove design like that on my site: http://hikinghq.net/sgt_stove/sgt_v8lite_instructions.html

I haven't run a test on this model yet to compare fuel efficiency.

[anneandbenhike]

You are describing what the engineers call "Thermal Overload" which basically means that the rate of heat transfer to the stove itself (heating and there-by vaporizing alcohol) is too efficient. Try decreasing the amount of air reaching the flame at the stove, reducing the size of the flame holes (punch-hole making with a smaller needle) or similar moves--there are some great links on the web.

[David S.]

Today I thought I would try out the tea candle stove...those little candles that have the aluminum base. I took the wax out of the base and filled the base with alchohol. The base holds almost exactly 1/2 an once. I have been struggling with the same problem of flames licking up the side of my pot.
I was very impressed with the results. No flames up the side of the pot but a nice even concentrated flame in the middle. I didn't time the boil but it brought 2 cups of cold water to a boil and held it at a boil for a good 20 seconds or so. Thats with only a half ounce of fuel....efficiency I was not able to achieve with my little V-8 stove. I was pretty impressed. This little thing appears to work embarrassingly well...and it won't even register on my postal scale so I am content to say that it weighs nothing. ;) After all the work I have put into making various other soda can stoves, this little thing appears to do the job quite gracefully...just letting the alchohol sit there and burn. Nothing fancy. Try it. Attatched is a pic of the little thing at work.

[Footslogger]

Today I thought I would try out the tea candle stove...those little candles that have the aluminum base. I took the wax out of the base and filled the base with alchohol. The base holds almost exactly 1/2 an once. I have been struggling with the same problem of flames licking up the side of my pot.
I was very impressed with the results. No flames up the side of the pot but a nice even concentrated flame in the middle. I didn't time the boil but it brought 2 cups of cold water to a boil and held it at a boil for a good 20 seconds or so. Thats with only a half ounce of fuel....efficiency I was not able to achieve with my little V-8 stove. I was pretty impressed. This little thing appears to work embarrassingly well...and it won't even register on my postal scale so I am content to say that it weighs nothing. ;) After all the work I have put into making various other soda can stoves, this little thing appears to do the job quite gracefully...just letting the alchohol sit there and burn. Nothing fancy. Try it. Attatched is a pic of the little thing at work.=============================
I'm guessing that your experiment was performed inside and without any wind, and thus no wind screen. Just wondering how well the Tea Candle stove would perform outside in cold temperatures, with moderate to high winds and with water in the 40 degree range.
===========================

[SGT Rock]

I made one of those, I really didn't like the performance in field conditions. You don't have the ability to increase the volume of fuel in colder or windy conditions since the total volume available is only 1/2 ounce - add to that the fact that if your stove is on a slight angle, then you loose some ofthat 1/2 ounce. I also found that although it did get bubbles forming and moving to the top, the real temperature achive when measured with a thermocouple was not 212 degrees, more like 190-200. Anyway, it does good at heating water, but not great.

[David S.]

Good point Footslogger. In my enthusiasm about my indoor results, I didn't think about how outdoor conditions would effect things. :-? Time to take it to the back deck and try it. I'll also try it with some 40 degree water. I don't think it will do nearly as well. For the weight though, you could bring it along for those warmer windless days and save some fuel. Use the V-8 type stove for windy, colder conditions.
Sgt Rock you make good points....sigh...off to the drawing board again. :-? Theres gotta be an optimum stove just for my pot. I thought about making a pepsi can style alcohol stove except with the fire holes on the inside top of the inner wall so the flames point inward rather than outward and hopefully focus the flame more on the bottem of the pot. What I think is happening is the alcohol is vaporizing to fast and making a flame much bigger than my stove needs.

[SGT Rock]

My general guidlines for a good stove:

-1 ounce capacity just in case.

-stable enought to hold a pot up even when on a slightly uneven surface.

-flame concentrated to the center of the pot whenever possible. The flames should not shoot up the sides of the pot since this is wasted energy.

-the flame should be blue, with the ends just turning yellow. This is achived for each different stove by adjusting pot heght.

-any stove should be able to achive a rolling boil consistantly with a pint of water in almost any condition with 3/4 ounce alcohol. It should be able to achive a roiling boil unconditionally with 1 ounce fuel. 1/2 ounce alcohol is a best situation fuel consumption and for some tasks like making some hot water it should be sufficient.

[Dances with Mice]

I thought about making a pepsi can style alcohol stove except with the fire holes on the inside top of the inner wall so the flames point inward rather than outward and hopefully focus the flame more on the bottem of the pot. What I think is happening is the alcohol is vaporizing to fast and making a flame much bigger than my stove needs.

The miniature cat burner, construction steps show in my gallery, keeps the flames focused in the middle of the burner. Getting it centered under the pot, of course, is your responsibility. Weighs 0.4 oz. http://www.whiteblaze.net/gallery/showphoto.php/photo/5422/password/0/sort/1/cat/500/page/2

There is also a very stable, one piece, combination windscreen and potholder that goes along with the burner to complete the stove. I just finished constructing another one tonight and I'll try to post the photos tomorrow after I edit them a bit. I also want to take the windscreen/potholder to work and weigh it.

[jlb2012]

Today I thought I would try out the tea candle stove...those little candles that have the aluminum base. I took the wax out of the base and filled the base with alchohol. The base holds almost exactly 1/2 an once. I have been struggling with the same problem of flames licking up the side of my pot.
I was very impressed with the results. No flames up the side of the pot but a nice even concentrated flame in the middle. I didn't time the boil but it brought 2 cups of cold water to a boil and held it at a boil for a good 20 seconds or so. Thats with only a half ounce of fuel....efficiency I was not able to achieve with my little V-8 stove. I was pretty impressed. This little thing appears to work embarrassingly well...and it won't even register on my postal scale so I am content to say that it weighs nothing. ;) After all the work I have put into making various other soda can stoves, this little thing appears to do the job quite gracefully...just letting the alchohol sit there and burn. Nothing fancy. Try it. Attatched is a pic of the little thing at work.

I've been using this approach for the last year or so with my beer can pot - it's the only approach that minimizes the flames up the side of the pot problem I was having with the other burners. With respect to boiling 2 cups of water - for the most part I don't try - I boil 1.75 cups of water which is enough for most of my meals (typically Liptons noodle or rice dinners). In the colder weather I sometimes don't get a full rolling boil but in those cases I just put in a little more alcohol and light it again after it goes out the first time. One nice thing about this approach is that once the water is boiling you can blow out the tea candle burner and pour the excess alcohol back into the fuel bottle. This is why I no longer put any fiberglass into the tea candle cup - so I can pour the excess back into the bottle. Other notes - beer can pot is a Heineken 24 ounce minikeg - ridges help it hold its shape and make it easier to pickup. The actual cooking is done in a zip lock bag in a cozy - the beer can is only there for boiling the water.

In general it is not as fast as some stoves but it works well enough for me.

[peter_pan]

Try making one of Atlanta Randy's ( Sgt Rock's site) Potted meat can Stoves.....they are super...no moving parts....cost $0.20 for the can. ....can be made in less than 5 minutes with nothing but a push pin.... I use an old alum BSA mess kit pot with the handle removed...capacity 0.8 qt....put the pot on the can....instant pressure...great blue flame....Boils two full cups - 16 oz- in 4 minutes...on 0.5 oz of alcohlol...The stove complete is 00000.33 oz.....yes 9-10 grams as close as I can measure.

:-? Wgt 1/3 of a sode can stove :)
cost less than 12 of a soda can stove :p
pressurized. Not all soda stoves are ;)
no moving parts, most pressure soda cans have a screw ;)
no pot stand needed :clap
replacable in any trail town with out tools ( borrow push pin off the employee BB)
uses less alcohol
fits in any pot and most all cups for storage
boils 16 oz water in 4 minutes :banana
PS.....You can eat the meat first

[David S.]

On the flames licking up the side of the pot. I have noticed that when I remove the windscreen, the flames do a better job of staying centered under the pot. I overheard a firefighter saying that fire will gravitate to where the oxygen is. I think that may be what is happening under my pot. Maybe I need more air holes around the bottem of the windscreen and maybe more open space around the edge of the pot.

[Dances with Mice]

On the flames licking up the side of the pot. I have noticed that when I remove the windscreen, the flames do a better job of staying centered under the pot. I overheard a firefighter saying that fire will gravitate to where the oxygen is. I think that may be what is happening under my pot. Maybe I need more air holes around the bottem of the windscreen and maybe more open space around the edge of the pot.Yeah! David, you just did what many scientists I work with can't - you observed an effect and postulated not one but two hypotheses! That's outstanding, and I am not being at all saracastic. Good job.

From my observations - if the stove is starved of oxygen you'll get "Blumps". That's a word I invented, it means a series of small explosions. If the stove doesn't have enough air then it will give off unburned alcohol vapors. When they mix with air and reach some critical level the stove will go "BLUMP! pause BLUMP! pause BAH LUMP!" as the vapors ignite.That means you don't have enough airholes in your windscreen, it could also mean the open space around the pot is too small and vapors are backing up since they can't escape.

If the flames rise above the pot it means your stove is burning welll and your pot is too low.

[Dances with Mice]

There is also a very stable, one piece, combination windscreen and potholder that goes along with the burner to complete the stove. I just finished constructing another one tonight and I'll try to post the photos tomorrow after I edit them a bit. I also want to take the windscreen/potholder to work and weigh it.


http://www.whiteblaze.net/gallery/showphoto.php/photo/5831/password/0/sort/1/cat/500/page/1

[Smooth03]

It is important to remember that since den. alcohol simply can't burn at as high a temperature as white gas that you want to transfer the heat as efficiently as possible. I know titanium is expensive but if you can swing the 70 bucks and hold on to it for the rest of your life its worth it. I don't remember the exact times so I won't post any numbers but a year ago I tested my titanium pot versus my aluminum pot with all variables constant except the type of pot. The Titanium pot won by a significant margin, nothing drastic but enough time to make you stop and think about the type of pot you use.

Another easy trick is to pre- and post-soak your meal. This is especially easy if you are using rice since with rice you just cook until there is no more water.. Hot water simply increases the rate at which pasta and rice absorbs water but is not a necessity.

A "windscreen" that envelops as much of the sides of the pot will also help. This is especially true if the outside air is extremely cold, i.e. 20 degrees. Even if the windscreen only warms the immediate inch of air surrounding the pot to 50 degrees that’s a huge difference.

I'm rambling now. I'll stop.

[Ridge]

The alcohol stoves in my past all worked well, but only when conditions where good. It's still my second choice of stoves. I like to winter hike and we know what very low temps do to alcohol. Transporting fuel on public transportation has gotten to be a big hastle to, I killed a half day looking for alcohol before hitting the trail after flying across the US. I just stay content with my woodburner, currently at 16 ozs. I hope one day to get a titanium model.

[zelph]

jlb2012 (http://www.whiteblaze.net/forum/member.php?6-jlb2012)

http://www.whiteblaze.net/forum/images/Eloquent/statusicongreen/user-offline.png
http://www.whiteblaze.net/forum/images/icons/icon1.png http://www.whiteblaze.net/forum/images/Eloquent/miscgreen/quote_icon.png Originally Posted by David S.


Today I thought I would try out the tea candle stove...those little candles that have the aluminum base. I took the wax out of the base and filled the base with alchohol. The base holds almost exactly 1/2 an once. I have been struggling with the same problem of flames licking up the side of my pot.
I was very impressed with the results. No flames up the side of the pot but a nice even concentrated flame in the middle. I didn't time the boil but it brought 2 cups of cold water to a boil and held it at a boil for a good 20 seconds or so. Thats with only a half ounce of fuel....efficiency I was not able to achieve with my little V-8 stove. I was pretty impressed. This little thing appears to work embarrassingly well...and it won't even register on my postal scale so I am content to say that it weighs nothing. ;) After all the work I have put into making various other soda can stoves, this little thing appears to do the job quite gracefully...just letting the alchohol sit there and burn. Nothing fancy. Try it. Attatched is a pic of the little thing at work.






I've been using this approach for the last year or so with my beer can pot - it's the only approach that minimizes the flames up the side of the pot problem I was having with the other burners. With respect to boiling 2 cups of water - for the most part I don't try - I boil 1.75 cups of water which is enough for most of my meals (typically Liptons noodle or rice dinners). In the colder weather I sometimes don't get a full rolling boil but in those cases I just put in a little more alcohol and light it again after it goes out the first time. One nice thing about this approach is that once the water is boiling you can blow out the tea candle burner and pour the excess alcohol back into the fuel bottle. This is why I no longer put any fiberglass into the tea candle cup - so I can pour the excess back into the bottle. Other notes - beer can pot is a Heineken 24 ounce minikeg - ridges help it hold its shape and make it easier to pickup. The actual cooking is done in a zip lock bag in a cozy - the beer can is only there for boiling the water.

In general it is not as fast as some stoves but it works well enough for me.







I'm doing a little research on beer cans being used as pots. This is the first thread that I could find that mentions the Heineken can being used as a pot. Just thought I would bump up a little nostalgia stuff. :)

edited to add the date of the post that I quoted: 12-09-2004, 07:32

[MDSection12]

I'm doing a little research on beer cans being used as pots. This is the first thread that I could find that mentions the Heineken can being used as a pot. Just thought I would bump up a little nostalgia stuff. :)

edited to add the date of the post that I quoted: 12-09-2004, 07:32
I have a Heine pot for nostalgia, but I use your 2 cup, flat bottom Fosters for field use. That little guy is perfect! The only drawback is I'm too nervous to put it in the fire, so I use a 10 cm IMUSA when I expect to be cooking (boiling) by fire. Thanks for making cool stuff!

[zelph]

I have a Heine pot for nostalgia, but I use your 2 cup, flat bottom Fosters for field use. That little guy is perfect! The only drawback is I'm too nervous to put it in the fire, so I use a 10 cm IMUSA when I expect to be cooking (boiling) by fire. Thanks for making cool stuff!

The flat bottom ones stand up very well to wood fires.....but.....the graphics get all dirty:D One of the nicest things about foster pots is the graphics and finish coating on the aluminum. It's not pourous like Imusa and other aluminum pots. No graphis on pots....boring!:D

Wait till you see the new pot I come out with this month...the graphics will knock your eyeballs out:banana

[Starchild]

You are describing what the engineers call "Thermal Overload" which basically means that the rate of heat transfer to the stove itself (heating and there-by vaporizing alcohol) is too efficient. Try decreasing the amount of air reaching the flame at the stove, reducing the size of the flame holes (punch-hole making with a smaller needle) or similar moves--there are some great links on the web.

Problem with restricting air is that the alcohol will evaporate anyway, but not burn. This is very evident if you try to run a air restricted alky stove indoors you can get slightly high and a nauseous feeling from the fumes that puts off. With proper air it is much cleaner. Air restriction is not a good way to regulate such a stove, better to have a smaller opening for fuel to be exposed to air.

[RED-DOG]

I went to SGT Rock site and can't find Atlanta Randy's potted Meat stove, i am assuming you set the pot directly on the stove without a stand, and poke the holes about half way up the can, I am going to try and make one tonight, i have a few Alchy stoves and they all work OK and i have been looking for a new design and the potted meat one sounds pretty interesting.

[zelph]

I went to SGT Rock site and can't find Atlanta Randy's potted Meat stove, i am assuming you set the pot directly on the stove without a stand, and poke the holes about half way up the can, I am going to try and make one tonight, i have a few Alchy stoves and they all work OK and i have been looking for a new design and the potted meat one sounds pretty interesting.

If we go back that far in time the potted meat(Fancy Feast for cats) stove may have become what is known as the SuperCat stove. Maybe that was what they were doing back then. Not sure, just a guess. The Supercat stove worked great with 1/2 oz fuel, boiled 2 cups in 4 min. But!!!! it has it's down sides. I remember Jason Klass having difficulties making the stove work. Jason has youtube videos of stoves and stuff. He used to post here for a spell and branched off on his own little blog. Some of you may know of him.

The "Supercat" was my inspiration for making one piece stoves. (StarLyte, Fancee Feest, Budlyte Super Stove, Venom Super Stove, GOTO, Ring of Fire, Cobalt and the Cobalt Blue Soloist) All those stoves have integrated pot supports. Just one piece...user friendly;) all those stoves can be found in the DIY gear forum. The designs originated here on Whiteblaze.

Share your designs with everyone in the DIY Gear forum.

Partial Peek at graphics on new beer can pot coming this month. Nautical theme

http://img.photobucket.com/albums/v228/obijiwa/th_1Conquistador_zps4a50b27f.jpg (http://smg.photobucket.com/user/obijiwa/media/1Conquistador_zps4a50b27f.jpg.html)

[MDSection12]

The flat bottom ones stand up very well to wood fires.....but.....the graphics get all dirty:D One of the nicest things about foster pots is the graphics and finish coating on the aluminum. It's not pourous like Imusa and other aluminum pots. No graphis on pots....boring!:D

Wait till you see the new pot I come out with this month...the graphics will knock your eyeballs out:banana
Wow, they hold up in a fire? Good to know! Thanks!


Partial Peek at graphics on new beer can pot coming this month. Nautical theme

http://img.photobucket.com/albums/v228/obijiwa/th_1Conquistador_zps4a50b27f.jpg (http://smg.photobucket.com/user/obijiwa/media/1Conquistador_zps4a50b27f.jpg.html)
I won't ruin the surprise, but please don't tell me you're pouring that out. ;)

[zelph]

Wow, they hold up in a fire? Good to know! Thanks!


I won't ruin the surprise, but please don't tell me you're pouring that out. ;)

No, it wasn't poured out.................I did not consume it:) I get the cans directly from the brewery.

I've done a lot of testing using wood as my fuel of choice. I'm old school;)

As long as the pot is filled with water there will be no damage. Here is a video of a Ridgline Foster pot being used to test a Titanium windscreen/stove design:


https://www.youtube.com/watch?v=OsUx4P0tWNs

http://img.photobucket.com/albums/v228/obijiwa/th_1Conquistador_zps4a50b27f.jpg (http://smg.photobucket.com/user/obijiwa/media/1Conquistador_zps4a50b27f.jpg.html)http://img.photobucket.com/albums/v228/obijiwa/th_1Conquistador_zps4a50b27f.jpg (http://smg.photobucket.com/user/obijiwa/media/1Conquistador_zps4a50b27f.jpg.html)http://img.photobucket.com/albums/v228/obijiwa/th_1Conquistador_zps4a50b27f.jpg (http://smg.photobucket.com/user/obijiwa/media/1Conquistador_zps4a50b27f.jpg.html)http://img.photobucket.com/albums/v228/obijiwa/th_1Conquistador_zps4a50b27f.jpg (http://smg.photobucket.com/user/obijiwa/media/1Conquistador_zps4a50b27f.jpg.html)http://img.photobucket.com/albums/v228/obijiwa/th_1Conquistador_zps4a50b27f.jpg (http://smg.photobucket.com/user/obijiwa/media/1Conquistador_zps4a50b27f.jpg.html)

[Kc Fiedler]

You are describing what the engineers call "Thermal Overload" which basically means that the rate of heat transfer to the stove itself (heating and there-by vaporizing alcohol) is too efficient. Try decreasing the amount of air reaching the flame at the stove, reducing the size of the flame holes (punch-hole making with a smaller needle) or similar moves--there are some great links on the web.

It sounds like reducing the oxygen reaching the stove might help a bit too if the flame is too intense. Could you try reducing the air flow? It would take longer to boil probably but might be more efficient and maybe reduce the flame that escapes up the side... just a guess.

[squeezebox]

Try the 24 oz beer can instead of the 12 oz. larger area to cut out of the top bigger flame. no guarentes just try it for yourself. Any way to cover 1/2 the top to help control the size of the flame. My pocket rocket has this nice little valve on the side I can turn up or down, and the whole thing weighs about 4-6 oz more than your OH stove